This invention relates to telephone systems and particularly to a device for providing privacy for a particular telephone line operated device which is off hook such that other telephone operated devices sharing a line cannot interrupt.
In many commercial and residential telephone installations there are a number of telephone line operated devices sharing a common exchange line. In such installations, particularly where the telephone line operated device is a modem or fax machine, it is important that hen these devices are in use other devices on the same line cannot interrupt unless so authorized by the user of the telephone line operated device that is actively connected to the line.
There are many arrangements known in the art of telephone systems for providing privacy on a telephone line operated device which shares the common exchange line with other devices when such are in use.
There are a number of known problems with these privacy devices. A major problem with some of these privacy devices is that each telephone line operated device need to be physically connected so that the privacy device can sense when one is in use. For example, D. J. Ryan U.S. Pat. No. 4,825,465 issued Apr. 25, 1989 shows such a device. This is not practical in an office or residence where there are individual jacks in separate rooms.
Another problem with some of these privacy devices is that the mechanism for allowing a telephone line operated device to interrupt a line already in use is controlled by the telephone line operating device that is interrupting the existing connection. K. L. Chan et al. U.S. Pat. No. 4,747,128 issued May 24, 1988 shows a telephone privacy protector having a voice connecting circuit, a control circuit a trigger and an override switch. This switch operates such that anyone wanting to interrupt a line that is already in use can press the override switch and do so. However, it is the telephone line operated device that is off hook and therefore in use that should control the interruption of another telephone line operated device since an interruption in a modem or a fax transmission can significantly affect the information sent or received.
It is an object of the present invention to provide a telephone privacy protector that allows the operator of the telephone line operated device that is off hook to authorize other telephone line operated devices to connect to the same line. It is a further object of the invention to provide a telephone privacy jack that is easily installed whereby the privacy jack is inserted into the common exchange line jack and the telephone line operated device is then inserted into the privacy jack.